Starry triggerfish

Abstract: Collagen from alternative sources is being considered for various industrial applications. This study presents the extraction of collagen, a product of high value, from the skin of starry triggerfish (Abalistes stellatus). The feasibility of utilising the extracted collagens for fabrication of biodegradable food packaging film via casting method has also been investigated. The extracted acid solubilised collagen (ASC) and pepsin solubilised collagen (PSC) with yields of 7.1 ± 0.2% and 12.6 ± 0.1% (wet weight basis), respectively, were identified as type I collagen. ATR-FTIR spectra displayed that both ASC and PSC molecules had an intact triple helical structure stabilised mainly by hydrogen bonds. The net charge of ASC and PSC became zero at pHs of 5.6 and 5.4, respectively as determined by zeta potential titration. Furthermore, ASC based packaging film showed the highest tensile strength (TS), elastic modulus (E) and contact angle (θ), but the lowest elongation at break (EAB) and water vapour permeability (WVP) (P < 0.05), compared with the PSC film. Increased glass-transition temperature (Tg) and endothermic melting temperature (Tm) accompanied with higher enthalpy (ΔH) were detected in the ASC film, indicating a strong protein–protein interaction in the film network. Based on thermal analysis, the ASC film contained higher heat-stable mass residues (30.9%, w/w) as compared to the PSC film (14.3%, w/w) in the temperature range of 50–600 °C. The microstructure of the ASC film had a finer and smoother surface without layering or cracking phenomenon; however, a coarser surface was observed in the PSC film. Therefore, the skin of starry triggerfish could serve as a potential source of collagen for food packaging film applications.

Abstract: Gelatin is widely used in the food, pharmaceutical, and cosmetic industries. The demand for gelatin increases every year, gelatin derived from pigs and cows is the main source of gelatin in the market. Gelatin that is sourced from other animals such as from poultry and fish is only about 1%. Gelatin from fish becomes a better prospect to develop. Gelatin raw materials can be obtained from the skin, bones, and fish fins. Fish skin is a waste processing of fishery products. The extraction method, fish type and intensity of the treatment determines the fate of produced gelatin. The purpose of this research determined the amino acid profile of starry triggerfish gelatin which was extracted using 2.5% sulfuric acid. In addition, it also contains the physical properties of gelatin which contains the yield, gel strength and viscosity. The results showed that gelatin products had a composition of essential and non-essential amino acids with the highest percentage of glycine, and then proline, alanine, glutamate acid and arginine. While the lowest was amino acid tyrosine. The average yield of gelatin reached 15.4%, gel strength 15.4 N and viscosity 7,2 cP. The use of sulfuric acid with high concentration can decide amino acids that have been formed so the amino acid chain of the broken gelatin causes the gel strength decreased. While the use acid solution with low concentration can result in small gel strength because collagen converted into gelatin is less. So the type of acid and optimal concentration will affect the acid amino composition and physical characteristics. This is related to the structure of the gelatin Ala-Gly-Pro-Arg-Gly-Glu-Hyd-Gly-Pro which affects the gel strength of the gelatin, where the length of the amino acid chain, the gel strength of gelatin is also getting better. Gel strength will affect viscosity and yield.

Abstract: The following members of the genus Hypocreadium are described or redescribed: Hypocreadium cavum from the starry triggerfish, Abalistes stellatus, Swain Reefs, Great Barrier Reef; Hypocreadium patellare ‘Typical form’ from Abalistes stellatus, Swain Reefs, the masked triggerfish, Sufflamen fraenatum, Ningaloo, Western Australia and off New Caledonia and the titan triggerfish, Balistoides viridescens, off Lizard Island, Great Barrier Reef; Hypocreadium patellare ‘Atypical form A’ from the black-bar triggerfish, Rhinecanthus aculeatus, off Lizard Island and Palau and blackbelly triggerfish, R. verrucosus, off Palau; Hypocreadium patellare ‘Atypical form B’ from the yellow-spotted triggerfish, Pseudobalistes fuscus off Lizard Island; Hypocreadium picasso n. sp. from Rhinecanthus aculeatus, off Lizard Island and Palau, characterised by its broadly pyriform shape and lack of an anterior notch. A key to the species of Hypocreadium is presented. The similarity of the genus Lutianotrema to Hypocreadium is pointed out, but both known species of Lutianotrema are described with ‘dorsal’ oral suckers.

Abstract: The potential of aqueous two-phase system (ATPS) for the purification and recovery of proteinase from albacore tuna (Thunnus alalunga) liver was explored. Influence of phase compositions such as type of phase forming salts, PEG molecular weight, concentration of salt and PEG, pH of the system and NaCl addition on partitioning of proteinase was investigated. ATPS comprising PEG1000 (25%, w/w) and NaH2PO4 (20%, w/w) at pH 7.0 provided the best condition for the maximum partitioning of proteinase into the top phase and gave the highest purification factor (5.58-fold) and specific activity (20.65 unit/mg protein). The yield of 89.99% was obtained. The addition of NaCl up to a final concentration of 6% (w/w) decreased the degree of purification and enzyme recovery of proteinase. Based on electrophoresis and activity staining, the fractionated proteinases had the MW 21, 24, 30 and 34 kDa. The effect of fractionated proteinases on starry triggerfish (Abalistes stellaris) muscle hydrolysis was also studie...